Portable computers have recently become more powerful while at the same time becoming lighter and smaller. Peripheral devices are often used in conjunction with the portable computer to provide increased functionality, such as communications ability or enhanced data storage. One example of a peripheral device is a modem, which allows a user of a portable computer to communicate with other computers using telephone lines. Reduction in the size of peripheral devices has accompanied reductions in the size of portable computers.
Some portable computer systems and peripheral devices, modems in particular, have been designed recently such that the peripheral device is contained on a thin form factor computer card which plugs into a socket recessed within the body of the computer. Such peripheral devices can be carried along with the portable computer and inserted when needed.
Historically, each of the peripheral devices (e.g. modems, memory devices, facsimile, LANs, etc.) has required its own interface circuitry for connecting to the internal circuitry of a portable computer. This interface circuitry required a separate socket for each device, and thus more space in the portable computer. For example, a modem card and a memory card each required a separate socket, and thus two sockets were necessary even though only one was in use at a given time.
Recently, devices have been devised which allow some of these various forms of computer components to be plugged into the same socket of the computer, thereby reducing space required within the portable computer. For example, an international standard which defines the physical and electrical interface specifications for the interchangeability of memory and input/output cards was introduced by the Personal Computer Memory Card International Association (PCMCIA) jointly with the Japanese Electrical Industry Association (JEIDA) in September of 1991. In addition, a specification referred to as an Exchangeable Card Architecture (ExCA) specification, dated Dec. 20, 1991, has been issued by Intel Corporation of Santa Clara, Calif. The ExCA document describes specifications which manufacturers may use to provide interfaces which are ensured of allowing the memory and input/output cards for portable personal computers of different manufacturers to be interchanged.
A socket designed to these specifications allows cards, such as modem and flash memories, to be inserted, used, and removed interchangeably in the same socket. The computer systems used typically contained at least one socket recessed within the computer, such that the inserted computer card containing the modem, flash memory, etc., is protected by the body of the computer surrounding the socket in which the components are coupled.
The PCMCIA specification provides that the personal computer cards have a 68-pin connector located at the end of the card for transmitting signals between the computer and the card. Many system manufacturers desire to connect to critical signals on the integrated circuit card which are not available through the 68-pin connector. One example of such a need is found when the computer card is a modem card, in which case tip-ring connections between an external RJ11 jack and the modem card are needed. Such connections have typically been achieved through a second connector located along the rear edge of the computer card, i.e. the edge which faces to the outside of the computer which the card is inserted. This rear edge is opposite the 68-pin standard interface.
In the above example a two pin (tip and ring) connection is needed. In other applications a different number of pins may be needed in the second connector. The PCMCIA architecture includes a standard 15-pin interface along the rear edge of the PCMCIA card for coupling to external signals. Thus, in the above example, the modem card could include the 15-pin interface along its rear edge, using two of the pins to carry the tip-ring signals. In use, a 15-pin male attachment, coupled to the external RJ11 jack, is attached to the 15-pin connector on the inserted modem card. In the computer industry, PCMCIA cards designed with standard rear connectors such as the PCMCIA 15-pin standard connector, including modem cards, have been designed and developed at significant embedded cost. Other rear connectors, such as 14-pin connectors on Intel PCMCIA computer card products, have been used as well.
Another method of transferring external signals to a computer card, which can replace or be additive to the rear connectors, is described in a co-pending application, Ser. No.08/099,135, "Method and Apparatus for Propagating Signals on Integrated Circuit Cards", applicant David C. Scheer, filed Jan. 26, 1993, and assigned to the assignee of the present invention. The "sideswipe" invention disclosed in the above pending application can provide tip-ring connections to a modem card, for example, through embedded contacts in the side of the computer card receptacle. One advantage of such a configuration is the elimination of the need to directly attach an external connector to the rear of the inserted modem card.
One problem which exists is that an integrated circuit card designed with rear external connectors may be desired for use in a side-contacting configuration as well, and it is thus desired to be able to adapt an integrated circuit card which has been designed with rear connections to a configuration which enables the card to receive signals through the side contacts as well.
Another problem which exists is the significant cost which can accompany a redesign of the existing integrated board circuitry, which is contained within the integrated circuit card, when the location of input signal contacts is changed.
Another problem which exists is that of unwanted electromagnetic radiation interference which can arise if conductor runs on the integrated circuit board carrying the input signals are lengthened to accommodate the change in the location of the input signal contacts, absent a substantial redesign of the existing integrated circuit board circuitry.